Strapping machine for strapping an article with a weldable plastic strap

ABSTRACT

The present disclosure provides a strapping machine for strapping an article. The strapping machine includes a machine framework, a machine table for accommodating the article during the strapping operation, a feed device for transporting the article onto the machine table in a conveying direction, a strapping device, which is assigned to the machine table and is intended for strapping the article with the plastic strap, a removal device for transporting the strapped article away from the machine table in the conveying direction, and an ejecting device arranged in the region of the machine table and intended for ejecting an article directly from the strapping device in a direction transverse to the conveying direction.

PRIORITY

This application claims priority to and the benefit of German Patent Application No. 10 2018 219 010.0, filed Nov. 8, 2018, the entire contents of which is incorporated herein by reference.

FIELD

The present disclosure relates to a strapping machine for strapping an article, such as a stack of products or a packaging carton, with a weldable plastic strap.

BACKGROUND

The basic components of a strapping machine include a machine framework, a machine table for accommodating the article during the strapping operation, a feed device for transporting the article onto the machine table in a conveying direction, a strapping device assigned to the machine table and intended for strapping the article with the plastic strap, and a removal device for transporting the strapped article away from the machine table in the conveying direction.

The problem to which the present disclosure is directed is that it is necessary, in a packaging line in which one station is formed by a strapping machine, for defective articles (for example a stack of products comprising too few products or unsatisfactory products or else a damaged packaging carton) to be taken out of the handling process. In the case of conventional strapping machines, it is not possible, in the standard configuration, for an article that has been marked or identified as being defective to be ejected laterally. Defective packages are ejected via a separate machine component, for example by an ejector that is adjacent to the strapping machine and with the aid of which a defective package is ejected from the handling process in a direction transverse to the conveying direction.

This additional machine component disadvantageously means that a packaging line which involves a strapping machine requires a greater set-up surface area and overall installation length.

SUMMARY

The present disclosure is directed to improving a strapping machine such that an operation of ejecting an article that has been identified as being defective is achieved without any additional set-up surface area and, in particular, overall installation length of the machine.

This improvement is achieved via an ejecting device arranged in the region of the machine table and intended for ejecting an article directly from the strapping device in a direction transverse to the conveying direction.

On account of the ejecting device being arranged according to the present disclosure in the region of the machine table, for example in the form of a pusher, that acts on a defective package from the side and ejects the package from the machine table to the side in a direction transverse to the conveying direction, there is no need for any additional set-up surface area and overall installation length for the ejecting device.

A particularly advantageous embodiment is one in which the ejecting device is integrated in the machine table. This can be realized, for example, by transverse and longitudinal conveyor belts installed in the machine table. This means that there is no need to have any additional structures above the machine table for the integrated ejecting device.

One embodiment of an integrated ejecting device is provided by a ball-grid conveyor belt, which is known in the field of handling technology, that forms the surface of the machine table and by way of which it is possible to generate two horizontal movement components of the article in and transverse to the conveying direction independently of one another.

The German expression “Kugelraster-Förderband” (ball-grid conveyor belt) has been coined by the author of this application and relates to a conveyor-belt solution known as “uni QNB ball belt” from Ammeraal Beltech Holding B.V., 1700AA Heerhugowaard, Netherlands, which sells a modular plastic conveyor belt that has separately drivable balls arranged in grid form in the belt and goes by the name given above. With the aid of this so-called “ball-grid conveyor belt”, an article arranged thereon can be maneuvered in practice in any desired manner in an x-y plane.

This allows optimal realization of the ejecting device according to the present disclosure in the machine table of the strapping machine.

The ejecting device provided according to the present disclosure can be implemented particularly straightforwardly in a longitudinal strapping device.

To vary the further handling of an ejected, defective article, it is possible in certain embodiments to provide a transverse conveying device alongside the machine table for transporting the ejected article onward. The transverse conveying device can be formed in particular, in turn, by a ball-grid conveyor belt (as explained above) and/or a conventional roller conveyor and/or a corresponding conveyor-belt arrangement. In particular, if use is made of a ball-grid conveyor belt, it is possible, once the article has been ejected, for the article to be transported away again in two different directions by said transverse conveying device. A defective article can therefore be fed very straightforwardly selectively to a repair station or to disposal means by virtue of being transported away in different directions.

Further features, details, and advantages of the present disclosure can be gathered from the following description of an exemplary embodiment with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a perspective illustration of a strapping machine.

FIG. 2 shows a plan view of the strapping machine according to FIG. 1.

DETAILED DESCRIPTION

As can be seen from the drawings, the strapping machine has a machine framework 1, on which a machine table 2 serves to accommodate the article 3, which is illustrated in this case by way of example in the form of a packaging carton, during the strapping operation. The strapping machine shown here is a longitudinal strapping machine of fully conventional design, as far as the handling of the strap around the article 3 and also the formation of a welded loop are concerned. Therefore, a feed device 4, which is located upstream of the machine table 2, as seen in the conveying direction F, and is in the form of a corresponding conveyor belt, is used to convey the article 3 onto the machine table 2 in the conveying direction F. The machine table comprises the conventional components of a strapping device UE, such as the lateral guide jaws 5 and the pressing bars 6, which in the case shown are provided for two longitudinal strapping means, are arranged horizontally and in the conveying direction F and can be lowered onto the article 3 from above, under pressure, via corresponding vertical drives 7 on lateral retaining frames 8. The strap 9 itself is stored on supply rolls 10, 11 and, when the article 3 is moved onto the machine table 2 by the feed device 4, is positioned around the article 3, then guided downwards beneath the plane of the machine table 2 on the rear side of the article 3 with the aid of the manipulators, the so-called “needles” 21, arranged at the end of the pressing bars 6, and then drawn around the packaging carton to form a tensioned loop. The strap is then welded beneath the plane of the machine table 2, at an overlap location, with the aid of the welding head (not visible in the figures). This is all well-known prior art and conventional as far as longitudinal strapping machines are concerned, and there is therefore no need for any more specific explanation with reference to drawings.

Following this strapping operation, a satisfactory article 3 is transported away from the machine table 2 in the conveying direction F with the aid of a removal device 20, which is illustrated in this case in the form of a roller conveyor, for further handling.

For an article 3 that has been identified as being defective at any point in the handling process for the article to be ejected out of the process, the strapping machine according to FIGS. 1 and 2 provides an ejecting device 12, which is integrated in the machine table 2 and is a ball-grid conveyor belt 13. The latter comprises an endless conveyor belt which is made up of links and has balls 15, each projecting beyond the surface of the belt, arranged in a grid-like manner in the links. These balls can be driven in any desired directions, in particular in the x direction and y direction of the plane of the machine table 2, by separate, additional drive belts, which are arranged beneath the conveyor belt 14, and therefore, with the conveyor belt 14 at a standstill in the conveying direction F, the article 3 located thereon can be transported away in the direction transverse to the conveying direction F, that is to say can be transported away to the side in the y direction, by virtue of the balls 15 rotating about an axis of rotation located parallel to the conveying direction F. This means that a defective article 3 can be ejected laterally directly from the machine in the region of the machine table 2, and onto the adjacent ball-grid conveyor belt 16, from where it can be transported onwards, in a direction transverse to the conveying direction F, onto a roller conveyor 17.

As is not illustrated specifically in the drawings, it is possible for a defective article 3, following the lateral ejecting operation, to be transported away with the aid of the ball-grid conveyor belt 16 not onto the roller conveyor 17, but elsewhere, parallel to the conveying direction F again.

As can be seen, in particular, from the plan view according to FIG. 2, an ejecting device 12 integrated in the machine table 2 makes it possible for the overall length L of a strapping machine with an ejecting means to be reduced to the normal dimensions of a strapping machine without such an ejecting means. 

1. A strapping machine comprising: a machine framework; a feed device configured to move an article in a conveying direction; a machine table adjacent the feed device and supported by the machine framework, the machine table comprising an ejecting device configured to receive the article from the feed device and to move the article in either the conveying direction or a second direction transverse to the conveying direction; a strapping device configured to strap the article on the machine table; a first removal device adjacent the machine table and configured to receive the article from the ejecting device when the ejecting device moves the article in the conveying direction; and a second removal device adjacent the machine table and configured to receive the article from the ejecting device when the ejecting device moves the article in the second direction.
 2. The strapping machine of claim 1, wherein the second direction is perpendicular to the conveying direction.
 3. The strapping machine of claim 1, wherein the ejecting device is integrated in the machine table.
 4. The strapping machine of claim 2, wherein the ejecting device comprises a ball-grid conveyor belt that forms the surface of the machine table.
 5. The strapping machine of claim 1, wherein the strapping device is a longitudinal strapping device.
 6. The strapping machine of claim 1, wherein at least one of the first and second removal devices comprises a roller conveyor.
 7. The strapping machine of claim 6, wherein the second removal device comprises a ball-grid conveyor belt.
 8. The strapping machine of claim 7, wherein the second removal device further comprises a roller conveyor.
 9. The strapping machine of claim 1, wherein the feed device comprises a conveyor belt.
 10. A method of operating a strapping machine, the method comprising: moving, via a feed device, an article in a conveying direction onto a machine table; if the article on the machine table is not defective, moving, via an ejecting device of the machine table, the article in the conveying direction to a first removal device; if the article on the machine table is defective, moving, via the ejecting device of the machine table, the article in a second direction transverse to the conveying direction to a second removal device; and strapping the article via a strapping device if the article is not defective.
 11. The method of claim 10, wherein the second direction is perpendicular to the conveying direction.
 12. The method of claim 10, further comprising moving, via the second removal device, the article in the conveying direction. 